Systems and methods for treatment of BPH

ABSTRACT

A prostate therapy system is provided that may include any of a number of features. One feature of the prostate therapy system is that it can access a prostate lobe from the urethra. Another feature of the prostate therapy system is that it can deliver condensable vapor into the prostate to ablate the prostate tissue. Another feature of the prostate therapy system is that it can aspirate tissue from the prostate. Yet another feature of the prostate therapy system is that it can rotate during delivery of vapor and aspiration of tissue. Methods associated with use of the prostate therapy system are also covered.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/764,645, filed Feb. 11, 2013, now U.S. Pat. No. 8,801,702, which is adivisional of U.S. application Ser. No. 12/614,226, filed Nov. 6, 2009,now U.S. Pat. No. 8,372,065; which application claims the benefit under35 U.S.C. 119 of U.S. Provisional Patent Application No. 61/112,103,filed Nov. 6, 2008, titled “Systems and Methods for Treatment of BPH.”These applications are herein incorporated by reference in theirentirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to an apparatus and a related method forthe minimally invasive treatment of prostate tissue.

BACKGROUND OF THE INVENTION

Several systems and methods have been developed or proposed for thetreatment of prostate tissue to alleviate BPH symptoms or to treatprostate tissue. For example, tissue ablation methods have been based onRF ablation, microwave ablation, high intensity focused ultrasound(HIFU), cryoablation, radiation, surgery, and brachytherapy. Surgicalmethods with and without robotic assistance have been developed forremoval of diseased prostate tissue.

The apparatus, techniques and methods disclosed herein are adapted tofor the treatment of prostate tissue in general and more particularlyare focused on treatment of BPH (benign prostatic hyperplasia) andprostate cancer. BPH is a common problem experienced by men over about50 years old that relates to urinary tract obstruction. Prostatichyperplasia or enlargement of the prostate gland leads to compressionand obstruction of the urethra which results in symptoms such as theneed for frequent urination, a decrease in urinary flow, nocturia anddiscomfort.

Ablation of prostatic tissue with electromagnetic energy is well knownand has the advantage of allowing a less invasive approach. For example,high-frequency current in an electrosurgical ablation or prostatictissue causes cell disruption and cell death. Tissue resorption by thebody's wound healing response then can result in a volumetric reductionof tissue that may be causing urinary tract obstruction. Onedisadvantage of high-frequency current or laser ablation is potentialtissue carbonization that results in an increased inflammatory responseand far longer healing time following the ablation.

SUMMARY OF THE INVENTION

A method of extracting tissue from a patient's prostate is provided,comprising, introducing a tissue extraction member into a urethra of thepatient, rotating the tissue extraction member within the urethra,injecting condensable vapor from the tissue extraction member, andaspirating prostate tissue into the tissue extraction member.

In some embodiments, the method further comprises injecting highpressure liquid from the tissue extraction member into the urethra. Thehigh pressure liquid can be injected in pulses between 1 pulse/secondand 100 pulses/second. In some embodiments, the high pressure liquid isinjected radially outward from a longitudinal axis of the tissueextraction member. In other embodiments, the high pressure liquid isinjected at an angle of between 10 degrees and 90 degrees from alongitudinal axis of the tissue extraction member.

The method can further comprise expanding an occlusion member within theurethra distal to a tissue extraction member vapor exit port prior tothe injecting step. The method can further comprise expanding anocclusion member within the urethra proximal to a tissue extractionmember vapor exit port prior to the injecting step.

In some embodiments, the rotating step comprises rotating the tissueextraction member between 5 rpm and 10,000 rpm. The tissue extractionmember can be manually rotated, or can be rotated with a poweredrotating motor.

In some embodiments, the method further comprises heat sealing tissuemargins around extracted tissue in the prostate.

In one embodiment, injecting condensable vapor comprises deliveringbetween 100 W and 1000 W to the prostate. In another embodiment,injecting condensable vapor comprises delivering between 100 cal/gramand 600 cal/gram to the prostate.

In some embodiments of the method, the aspirating step comprisesremoving between 1 gram and 100 grams of prostate tissue from theprostate.

A prostate therapy system is provided comprising a condensable vaporsource, and a tissue extraction member adapted to be inserted into aurethra of an adult male human subject and to rotate within the urethra,the tissue extraction member having a vapor delivery port communicatingwith the vapor source and adapted to deliver condensable vapor to theprostate lobe and an aspiration port adapted to aspirate prostate tissueproximally into the ablation probe.

The tissue extraction member can further comprise a liquid ejection portcommunicating with a source of high pressure liquid. In someembodiments, the liquid ejection port and high pressure liquid sourceare adapted and configured to eject high pressure liquid in pulsesbetween 1 pulse/second and 100 pulses/second. The liquid ejection portis adapted and configured to eject high pressure liquid radially outwardfrom a longitudinal axis of the tissue extraction member. In someembodiments, the liquid ejection port is adapted and configured to ejecthigh pressure liquid at an angle of between 10 degrees and 90 degreesfrom a longitudinal axis of the tissue extraction member. In oneembodiment, the liquid ejection port is concentric with the vapordelivery port.

The prostate therapy system can further comprise a distal occlusionmember adapted to occlude the urethra distal to the vapor delivery port,and a proximal occlusion member adapted to occlude the urethra proximalto the vapor delivery port.

In some embodiments, the prostate therapy system further comprises apowered rotating motor configured to rotate the tissue extraction memberbetween 5 rpm and 10,000 rpm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vapor energy delivery system and more particularly acut-away view of a handle portion of an instrument with an inductiveheating assembly for applying vaporization energy to a fluid flowtogether with a looped flow system for maintaining a circulating flow ofhigh energy vapor which is releasable on demand to flow through anextension member to interact with tissue.

FIG. 2 is a schematic view of the inductive heating assembly of FIG. 1.

FIG. 3 is a schematic view of a patient prostate and a first step ofintroducing a tissue extraction member into a patient urethra, showingtissue volumes targeted for extraction.

FIG. 4 is a perspective view of an instrument working end.

FIG. 5 is a sectional view of the working end of FIG. 4 illustratingschematically how tissue is extracted and sealed.

FIG. 6 is a schematic view of another instrument working end.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides for a vapor energy generation system thatcan be configured for introduction into a patient's urethra or prostate,or can be configured to access prostatic tissue trans-rectally orendoscopically. The system is configured to deliver a heated vapor, forexample water vapor, to tissue as described in the following U.S. patentapplications: Ser. No. 10/681,625, filed Oct. 7, 2003, now U.S. Pat. No.7,674,259, titled “Medical Instruments and Techniques forThermally-Mediated Therapies”; Ser. No. 11/158,930, filed Jun. 22, 2005,now U.S. Pat. No. 7,892,229, titled “Medical Instruments and Techniquesfor Treating Pulmonary Disorders”; Ser. No. 11/244,329, filed Oct. 5,2005, now U.S. Pat. No. 8,016,823, titled “Medical Instrument and Methodof Use”; and Ser. No. 11/329,381, filed Jan. 10, 2006, now U.S. Pat. No.8,444,636, titled “Medical Instrument and Method of Use”.

The generation and delivery of a collapsible, high energy vapor forvarious therapeutic procedures is further disclosed in systems with“remote” vapor generation systems or sources in Provisional PatentApplication Nos. 60/929,632, 61/066,396, 61/068,049, or with vaporgenerator in a handle or working end, or combination thereof, asdescribed in Provisional Application Nos. 61/068,130, 61/123,384,61/123,412, 61/126,651, 61/126,612, 61/126,636, 61/126,620.

FIG. 1 illustrates a vapor energy generation system 800 having a handle802 comprising an inductive heating system similar to that described inProvisional Application Nos. 61/123,416, 61/123,417, and 61/126,647. InFIG. 1, the handle 802 is coupled by temperature resistant fitting 806to a fluid source 810 that delivers liquid at a controlled flow rate andpressure. The liquid flow passes through a vapor generating inductiveheater 805 coupled to an electrical source and controller 820. Thesystem and handle is configured for a looped liquid/vapor flow toprovide vapor to working end or exit channel 822 to deliver the vapor toa tissue site. The system has inflow channel indicated at 824 andoutflow channel at 826 that can communicate with a collection reservoir830 and/or a negative pressure source 835. A valve 836, for example,operated by a footswitch is provided in outflow channel 826 to re-directvapor into the exit channel 822 and extension member 840.

A vapor energy generation system 800 as shown in FIG. 1 can be used forany surgical/medical application, with the extension member 840comprising a needle, an elongate probe or flexible catheter and othersimilar elongate delivery devices. This system can be used for acatheter for delivering energy for endovascular applications, fortreating respiratory tract disorders, for endometrial ablationtreatments or for needle ablation treatments. In the embodiment of FIG.1, an optional secondary heater 845 is shown with a concentric insulator846. This secondary heater can add further vaporization energy to vaporthat starts to flow through exit channel 822. The secondary heater canbe an inductive heater or a resistive heater that uses a microporousmaterial to provide a large surface area to apply energy to the vapor toremove any water droplets. This system can provide a vapor that is atleast 90% water vapor. The secondary heater is operatively coupled tothe electrical source and controller 820 by electrical leads (notshown).

FIG. 2 illustrates a vapor generating inductive heater 805 that in oneembodiment comprises a ceramic cylinder 850 with a bore 852 therein. Theceramic cylinder 850 can be approximately 1.0″ to 1.5″ in length and0.25″ in diameter with a 0.10″ bore 852, for example. The bore 852 ispacked with a plurality of small diameter hypotubes 855 that aremagnetic responsive, such as 316 stainless steel, for example. In oneembodiment, the hypotubes 855 are 0.016 thin wall tubes. A winding 860of one to ten layers having an axial length of about 1.0″ is providedabout the ceramic cylinder 850 for inductive heating of the hypotubes855 using very high frequency current from an electrical source. In oneembodiment the winding 860 can be 26 Ga. Copper wire with a Tefloncoating. It has been found that delivering at least 50 W, 100 W, 200 W,300 W, or 400 W with suitable flow rates of water can produce very highquality vapor, for example 90% vapor and better.

In FIG. 2, it can be seen that an inductively heated hypotube 855′ alsocan be spiral cut to provide flexibility for such an inductive heater tobe positioned in a catheter or probe working end. For example, suchflexible heatable elements can be carried in the bore of a flexible hightemperature resistant polymeric insulative member such to provide aflexible catheter that is configured for endovascular navigation. Aninsulation layer about an exterior of the inductive heater is not shown.In general, the vapor generating inductive heater 805 can configured toprovide a high quality condensable vapor media with precise parametersin terms of vapor quality, exit vapor pressure from a working end, exitvapor temperature, and maintenance of the parameters within a tightrange over a treatment interval. All these parameters can be controlledwith a high level of precision to achieve controlled dosimetry, whetherthe particular treatment calls for very low pressures (e.g., 1-5 psi) orvery high pressures (200 psi or greater) over a treatment interval, andwhether the treatment interval is in the 1-10 second range or 2 to 5minute range.

Now turning to FIG. 3, a sectional schematic view of a patient urethra105 and prostate 106 is shown with an instrument shaft navigated to apredetermined location in a patient urethra with an imaging system (notshown) to identify anatomical landmarks. An imaging system can beprovided in the form of a scope in a channel or a CCD. A system forvolumetrically removing prostate tissue is shown with FIG. 3 having anelongate tissue-extraction member 405 with a working end 410 advanced ina transurethral manner into the interior of a patient prostate. Thetissue regions indicated at 420A and 420B in the opposing lobes can betargeted for removal. The system also can contemporaneously thermallyseal of the margins of the extracted tissue volumes. An irrigationsystem (not shown) can be provided to supply a fluid to the lumen.

FIG. 4 illustrates that the tissue extraction member 405 and working end410 can be a rigid or slightly flexible assembly having a diameterranging from about 2 mm to 10 mm. The tissue extraction member caninclude at least one vapor delivery port 444 communicating with a vaporsource 100 and can be adapted to deliver condensable vapor to theprostate lobe. The tissue extraction member can also have at least oneaspiration port 480 in communication with a negative pressure source 470and adapted to aspirate prostate tissue proximally into the tissueextraction member. In one embodiment, the tissue extraction member isconfigured for jetting one of at least one fluid or vapor media fromsource of liquid media 450, for applying mechanical energy and thermalenergy to interfacing tissue for ablation and volumetric removal ofurethral tissue and adjacent tissue in a TURP-like procedure.

The working end can carry optional occlusion members 422 a and 422 bthat are expanded by a fluid inflation source 425. The occlusion memberscan be positioned on the proximal and distal portions of the tissueextracting member. The distal occlusion member 422 b is adapted toocclude the urethra distal to the vapor delivery port(s) 444, and theproximal occlusion member 422 a is adapted to occlude the urethraproximal to the vapor delivery port(s).

A central portion 430 of the working end is configured to rotate in thebody lumen. Rotation of the working end can be manual (e.g., physicalrotation of the instrument by the physician) or, alternatively, arotating mechanism 186 (e.g., a powered rotating motor) can be coupledto the working end 410 to automatically rotate the distal end of thedevice during ablation and aspiration. The rotating mechanism can beconfigured to rotate the ablation probe between 5 rpm and 10,000 rpm,for example. Further details of a method of rotating an ablation probein tissue are described in U.S. patent application Ser. Nos. 12/389,808and 61/123,416, which are incorporated herein by reference.

FIG. 5 shows a sectional view of the instrument working end 410, whereit can be seen that a first fluid flow system or condensable vaporsource 100 (for example, as shown in FIG. 1) is provided and is fluidlycoupled to at least one vapor inflow channel 452 that extends to atleast one vapor delivery port 444 in at least one recess 445 in theworking end. In this embodiment, the axis of each vapor delivery portcan be directed axially relative to the axis 448 of the instrument, oralternatively the axis can be directed radially outwardly from thedevice axis 448 at an angle of between about 10° to 90° relative to alongitudinal axis 448 of the tissue extraction member.

Still referring to FIG. 5, the instrument working end 410 includes asecond fluid flow system comprising a high pressure liquid source 450that is fluidly coupled to at least one vapor inflow channel 440 thatextends to at least one liquid ejection port 460 in at least onerecesses 445 in the working end. In this embodiment, the axis of eachliquid ejection port can be directed substantially axially relative tothe axis 448 of the instrument, or alternatively the axis can bedirected radially outwardly from the device axis at an angle of betweenabout 10° to 90° relative to a longitudinal axis 448 of the tissueextraction member.

As can be seen in FIG. 5, the instrument working end 410 furtherincludes a tissue extraction channel 465 coupled a negative pressuresource 470 for extracting disintegrated tissue, water and condensedvapor media from the treatment site. A computer controller 475 isoperatively coupled to the various systems and sources 100, 450 and 470to allow operation in unison.

Referring to FIG. 5, the instrument working end 410 can actuate theaspiration or negative pressure source 470 and controller 475 to suctiontissue into the working end recesses 445 and aspiration port 480,wherein in rotational operation, it can be understood that high pressureejection of vapor from outlets 444 will cause thermal damage, weakeningand denaturation of proteins and tissue constituents. At the same time,the high pressure ejection of liquid media from outlets 460 candisintegrate and disrupt the thermally damaged and weakened tissue toallow its extraction through ports 480. At the same time, the vapor flowand phase change energy release thereof contemporaneously seals orcoagulates the tissue margins to prevent bleeding. Following thetreatment, the body's wound healing response will heal the urethra as iscommon in TURP procedures.

It should be appreciated that the working end can have one or morestructures for fluid ejection to extract tissue, and can be actuatedrotationally and or axially. In one embodiment, the system can beconfigured to apply energy to tissue about only a selected radial angleof the tissue, for example 5°, 15°, 30°, 45°, 60°, 90° or 180° of thelumen. Similarly, the tissue ablation and extraction can have any axialorientation, for example to ablate and extract linear portions oftissue.

In another method, the working end as in FIGS. 4-5 can be providedwithout balloons and can be introduced interstitially to extract coresof prostatic tissue.

In another embodiment, a single fluid injection port can be utilizedwherein the vapor quality is such that vapor and water droplets in thesame flow can apply sufficient mechanical forces to disintegrate andvolumetrically remove tissue at the vapor-tissue interface. Thus, in oneaspect of the invention, the quality of the vapor, or combination ofjetted vapor with jetted water droplets can cut the thermally weakenedtissue. In another method, the fluid jet is pulsed at a rate of 1 to 100pulses/second. In another embodiment, the fluid jetting is pulsed withintermittent pulses of water and vapor at a high repetition rate withthe jetted water aliquot capable of disintegrating tissue and the vaporaliquot configured to weaken tissue and thermally seal tissue.

FIG. 6 illustrates another embodiment of working surface portion whereina vapor delivery port 490 is concentric around a liquid ejection port495 for interacting with and ablating tissue. The outlets can beconfigured is any type of surface structure for ablating tissue such asthe recesses of the working end of FIGS. 4 and 5.

In general, a method for treating a prostate disorder comprisesvolumetrically removing urethra and surrounding prostatic tissue in amethod performed with the ejection of jetted liquid and a heatedcondensable vapor from a device working end together with aspiration ofthe disintegrated tissue. In one aspect of the invention, the ejectionof vapor media applies sufficient thermal energy to substantially modifytissue, wherein the modification consists of at least one of weakeningcovalent bonds, denaturing proteins and disrupting collagen structures.Further, the ejection of liquid media applies sufficient mechanicalenergy for tissue removal wherein removal consists of at least one ofdisintegrating, cutting, excising and ablating tissue. In another aspectof the invention, the ejection of vapor media applies sufficient thermalenergy to heat seal or coagulate margins around the extracted tissue.Also, the methods of volumetrically removing tissue can be is performedcontemporaneous with imaging, such as ultrasound imaging.

In general, a method for sealing the tissue extracted tissue margins isaccomplished with the injecting condensable vapor media from a deviceworking end and aspiration of the disintegrated tissue wherein theenergy from the vapor comprises delivering at least 100 W, 250 W, 500 W,and 1000 W to the tissue. In another embodiment, injecting condensablevapor comprises delivering between 100 cal/gram and 600 cal/gram to theprostate.

In general, the method for treating a BPH can volumetrically removeprostatic tissue equaling at least 1 gram, 10 grams, at least 20 grams,at least 30 grams, at least 40 grams, at least 50 grams, and at least100 grams of tissue.

One embodiment of a method of extracting tissue from a patient'sprostate comprises introducing a tissue extraction member into a urethraof the patient, rotating the tissue extraction member within theurethra, injecting condensable vapor from the tissue extraction member,and aspirating prostate tissue into the tissue extraction member. Therotating step can comprise rotating the tissue extraction member between5 rpm and 10,000 rpm, such as with a powered rotating motor, forexample. In another embodiment, the tissue extraction member can bemanually rotated.

The method can further comprise injecting high pressure liquid from thetissue extraction member into the urethra. Injection of the highpressure liquid can be injected in pulses between 1 pulse/second and 100pulses/second. In some embodiments, the high pressure liquid can beinjected radially outward from a longitudinal axis of the tissueextraction member. In other embodiments, the high pressure liquid can beinjected at an angle between 10 degrees and 90 degrees from alongitudinal axis of the tissue extraction member.

In some embodiments of the method, an occlusion member is expandedwithin the urethra distal to a tissue extraction member vapor exit port.This step can be performed before injecting condensable vapor from thetissue extraction member, for example. In another embodiment, anocclusion member is expanded within the urethra proximal to a tissueextraction member vapor exit port. This step can be performed beforeinjecting condensable vapor from the tissue extraction member, forexample.

In another embodiment, a high speed rotational cutter can be usedcontemporaneous with a vapor ejection as described above to thermallycoagulate the margins about the removed tissue.

A system of the invention comprises an elongated tissue extractionmember with a working end configured for removing urethral tissue in apatient prostate, a vapor source in fluid communication with vapordelivery ports in the distal end, a liquid jetting source for ejectinghigh pressure liquid form the working end and a negative pressure sourcecoupled to a channel in fluid communication with a tissue aspirationport in the working end proximate the vapor delivery ports. The port(s)can be oriented distally relative to an axis of the tissue extractionmember, or at an angle relative to an axis of the tissue extractionmember, or oriented at a side of tissue extraction member substantiallyparallel to the axis of the tissue extraction member.

In general, the methods of the invention include delivery of acondensable vapor that undergoes a phase change to provide appliedenergy of at least 100 cal/gm, 250 cal/gm, 300 cal/gm, 350 cal/gm, 400cal/gm, 450 cal/gm, and 600 cal/gm of the vapor.

In another aspect of the invention, the treatment with vapor can beaccomplished under any suitable type of imaging. In one method, thesteps can be viewed by means of ultrasound or x-ray imaging. In onemethod, the introducer and energy delivery methods of the invention canbe imaged by ultrasound utilizing a trans-rectal ultrasound system.

In another aspect of the invention, the system may contemporaneously beused to deliver fluids to targeted locations in the prostate for medicalpurposes, such as for general or localized drug delivery, chemotherapy,or injections of other agents that may be activated by vapor or heat.

Although particular embodiments of the present invention have beendescribed above in detail, it will be understood that this descriptionis merely for purposes of illustration and the above description of theinvention is not exhaustive. Specific features of the invention areshown in some drawings and not in others, and this is for convenienceonly and any feature may be combined with another in accordance with theinvention. A number of variations and alternatives will be apparent toone having ordinary skills in the art. Such alternatives and variationsare intended to be included within the scope of the claims. Particularfeatures that are presented in dependent claims can be combined and fallwithin the scope of the invention. The invention also encompassesembodiments as if dependent claims were alternatively written in amultiple dependent claim format with reference to other independentclaims.

What is claimed is:
 1. A method of treating a patient's prostatecomprising: introducing a vapor energy delivery system into a urethra ofthe patient; rotating the vapor energy delivery system within theurethra; delivering a flow of fluid through at least one hypotube of thevapor energy delivery system; inductively heating the at least onehypotube to generate a condensable vapor from the flow of fluid; anddelivering the condensable vapor from the vapor energy delivery systemto the patient's prostate.
 2. The method of claim 1 further comprisingexpanding an occlusion member within the urethra distal to a tissueextraction member vapor exit port prior to the delivering step.
 3. Themethod of claim 1 further comprising expanding an occlusion memberwithin the urethra proximal to a tissue extraction member vapor exitport prior to the delivering step.
 4. The method of claim 1 wherein therotating step comprises rotating the vapor energy delivery systembetween 5 rpm and 10,000 rpm.
 5. The method of claim 1 wherein therotating step comprises manually rotating the vapor energy deliverysystem.
 6. The method of claim 1 wherein the rotating step comprisesrotating the vapor energy delivery system with a powered rotating motor.7. The method of claim 1 further comprising aspirating prostate tissueinto the vapor energy delivery system.
 8. The method of claim 7 whereinthe aspirating step comprises removing between 10 grams and 50 grams ofprostate tissue from the prostate.
 9. The method of claim 7 furthercomprising heat sealing tissue margins around the aspirated prostatetissue.
 10. The method of claim 1 wherein delivering condensable vaporcomprises delivering between 100 W and 1000 W to the prostate.
 11. Themethod of claim 1 wherein delivering condensable vapor comprisesdelivering between 100 cal/gram and 600 cal/gram to the prostate tissue.12. The method of claim 1 wherein the introducing step further comprisestransurethrally introducing the vapor energy delivery system into theurethra.